Definition: In this task, you are given an input list A. You need to convert all the alphabets in the list with a number representing their position in the English alphabet. E.g., replace A by 1, B by 2, a by 1, b by 2, and so on.
Input: ['8769', 'r', '1497', '5251', '975', '3285', '3867']

8769, 18, 1497, 5251, 975, 3285, 3867